Analysis by: Mark Joseph Manahan
ALIASES:

Win32/Qbot.BD trojan (Eset), JS/Downloader-FCQ (McAfee) , TrojanDownloader.JS.Quakbot.k (v)TrojanDownloader.JS.Quakbot.k (v) (Sunbelt)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Spammed via email, Downloaded from the Internet, Dropped by other malware

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 6,266 bytes
File Type: VBS
Memory Resident: No
Initial Samples Received Date: 12 Nov 2013
Payload: Downloads files

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following copies of itself into the affected system:

  • %Temp%\{Malware filename}.tmp

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}auskmt.pw/4
  • http://{BLOCKED}theusas.org/4
  • http://{BLOCKED}cmasn.net/4
  • http://{BLOCKED}skdfasjdmtf.org/4
  • http://{BLOCKED}psgrn.com/4
  • http://{BLOCKED}tmaksjdo.net/4
  • http://{BLOCKED}aqmi.net/4

It saves the files it downloads using the following names:

  • %Temp%\{random filename}.exe - BKDR_QBOT.EA

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.404.07
FIRST VSAPI PATTERN DATE: 12 Nov 2013
VSAPI OPR PATTERN File: 10.405.00
VSAPI OPR PATTERN Date: 12 Nov 2013

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Remove malware/grayware files dropped/downloaded by VBS_QBOT.EA

     BKDR_QBOT.EA

Step 3

Scan your computer with your Trend Micro product to delete files detected as VBS_QBOT.EA. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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